A sodium salt (A) when reacts with dilute HCI produces a salt and a colouless, rotten egg smelling gas (B). (B) when passed through lead acetate solution produces a black precipitate (C). Futher (C) on treatment with H_(2) O_(2) solution yields a white precipitate (D). Identify (A).

A sodium salt (A) when reacts with dilute HCI produces a salt and a co

1.	A sodium salt (A) when reacts with dilute HCI produces a salt and a colouless, rotten egg smelling gas (B). (B) when passed through lead acetate solution produces a black precipitate (C). Futher (C) on treatment with H_(2) O_(2) solution yields a white precipitate (D). Identify (A).
Answer» `H_(2) S` `Na_(2) S` `Na_(2) SO_(4)` `PbSO_(4)` Solution :As the GAS has rotten egg smell, so it may be `H_2S`. Hence the salf is sodium sulphide . Thus , `A = Na_2S, B= H_2S, C = PbS, D = PbSO_4` `underset((A))(Na_2S)+ 2HCL to 2NaCl + underset((B))(H_2S)` `Pb(CH_3COO)_(2) + H_2S to underset(("BLACK PPT."))underset((C))(PbS darr) + 2CH_3COOH` `PbS + 4H_2O_2 to underset(("WHITE ppt."))underset((D))(PbSO_4) darr + 4H_2O` .